Were My Bees Poisoned?
How Do I Clear Out a Colony That Was Poisoned?
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Cathie Fox asks: I believe one of my hives was poisoned. There is a pile in front of the hive. This colony was a combination of two weak splits waiting for a queen. (I used the newspaper method to combine them. ) My first impression was that my combination of the two hives had caused the dissonance and the death of the bees in front of the hive. After further investigation, I found that most of the dead bees had tongues hanging out. I realized it might be a pesticide. Now my question is how can I protect the other five hives? None of them had the pile of bees in front.
Rusty Burlew replies:
Some other conditions can cause the tongue to extend, but most often it is some kind of poisoning, as you suspect. The pile in front of the hive is also associated with poisoning. However, I wouldn’t worry too much about your other colonies.
The scouts from each hive go out to search for food sources, then they come back and report what they found to the other workers. Those workers go out in large numbers, so if the food supply is tainted, many bees may die at home and many more probably die in the field.
Usually, the scouts from different hives choose different food supplies. Just by accident, they find different sources. Since only one of your colonies seems affected, they were probably the only one to find or choose the tainted food. If several colonies had been feeding on it, they would have shown the same symptoms at roughly the same time.
Most, but definitely not all, of the insecticides break down quickly and don’t cause long-term problems. It’s the systemic pesticides, the ones taken up by the plants’ vascular system, that remain toxic for long periods. But unless you can pinpoint the source and remove it (unlikely), there is really nothing you can do except lock down your bees, which really isn’t acceptable either, except for very short time periods of a day or two.
Andy asks — My bees are dead from pesticide. What do I do know to clear them out?
Rusty Burlew replies:
The best thing to do with a dead colony is to take the hive apart and clean out all the dead bees. For a colony that most likely died of pesticide, I would let the open hive air out for a few days to get rid of any traces of the poison. However, pesticide contamination of the equipment is rare. Most of the bees die in the field or outside the hive such that the pesticide doesn’t accumulate. If you want to know exactly how long the pesticide might persist, you would have to find out the name of the chemical that caused the damage and then look up its characteristics.